with t0 as 
(
    select 
        *
        from grp
)
, t1 as 
(
    select 
        *
        from immigration
)
, t2 as 
(
    select 
        *
        from port
)
, t3 as 
(
    select 
        t1.port_code, 
        port_name, 
        group_code, 
        kind_code, 
        amt
        from t1
        inner join t2
        on t1.port_code=t2.port_code
)
, t4 as 
(
    select 
        port_code, port_name, 
        kind_code, group_name, 
        amt
        from t3
        inner join t0
        on t3.kind_code=t0.group_code
)
, t_in as
(
    select 
        port_code, port_name, 
        kind_code, group_name, 
        amt
        from t4
        where kind_code=110
)
, t_out as
(
    select 
        port_code, port_name, 
        kind_code, group_name, 
        amt
        from t4
        where kind_code=120
)
, t5 as 
(
    select 
        t_in.port_code, t_in.port_name, 
        --t_in.kind_code as 入国者数, 
        --t_out.kind_code as 出国者数, 
        t_in.amt as 入国者数, 
        t_out.amt as 出国者数
        from t_in
        inner join t_out
        on t_in.port_code=t_out.port_code
)
, t6 as 
(
    select 
        port_code as 港コード, 
        port_name as 港名, 
        入国者数, 
        出国者数, 
        入国者数 - 出国者数 as 差分
        from t5
        order by 差分 desc, 港コード desc
)
select * from t6 where 差分>0